In mass spectrometers ion sources are required to be heated up to high temperatures in order to provide optimum performance from the ion source. Typically an ion source block may be at temperatures as high as 150° c.
In order to attain these temperatures, a heater is required within the ion source block. A sensor is also placed in the ion source block so as to measure the temperature and prevent overheating.
Mass spectrometers are expensive instruments that are in constant use in many laboratories. Powerful heaters are desired to raise the temperature in the ion source up to the desired level as quickly as possible and therefore limit down time of the instrument. Therefore it would be desirable to provide a very powerful heater.
In the event of specific failure modes of a temperature sensor, powerful heaters in the source block may increase the temperature of the source to dangerously high levels at which damage may be caused to the mass spectrometer and to their users. In such circumstances, the mass spectrometer could incorrectly indicate that the temperature in the ion source chamber is below the actual temperature. This results in the heater continuing to heat the ion source, which potentially results in severe damage to the instrument requiring expensive repairs to the instrument.
It is therefore desirable to have a method of identifying faults in the source heater assembly mechanism so as to ensure the source heater will not cause severe damage to the mass spectrometer.